Blackboard.



T. H. COSTELLO.

BLAOKBOARD.

APPLIOATIoN FILED JUNE 4, 1909.

1,004,375, Patented stpt.26,1911.

witg/Str Iwata@ Qld/Mw Q9 i THOMAS II. COSTELLO, OF CHICAGO, ILLINOIS.

BLACKBOARD.

Specification of Letters Patent. Patentad Sept. 26, 1911.

Application led. .Tune 4, 1909. Serial No. 500,141.

have a metallic foundation or body. Such boards have many advantages inthat they stand hard wear, do not crack or break, do not absorb moisturefrom the air, and the metallic body protects the writing face againstmoisture in the room walls on which they may be installed. They areconveniently packed for shipment by placing them in rolls, and arereadily applied to the walls on which they are to be used. By means ofthis invention I am able to completely deaden or mul'He the noise causedby the impact of a crayon on an otherwise unprotected metallic board,and I am able to obtain that soft, smooth and velvety surface which is aquality greatly sought for in a blackboard. This I can do at smallexpense, and am able to provide a practical, cheap and satisfactorydevice.

In the drawings: .Figure 1 shows a front i view of a blackboard, theseveral layers being so removed as to illustrate their relativeposition; Fig. 2 is a section of the same on the line 2 2 of Fig. 1.

Further describing the Vsame, A represents a room wall to which myimproved blackboard is applied.

known commercially as vulcanized fiber,

hard calendered Manila paper or special material of the characterdescribed later, in which the coloring material and abrasive ashereinafter described is incorporated with vthe fiber in the process ofmanufacture.

In any case the selected material may be secured to the metallicfoundation by a suitable adhesive layer 2, such as asphaltum aint orvarnish. The application should e made under pressure which may be doneby passing the layers with cement when in a soft condition between themthrough suitable rollers or by subjecting them to the action of ahydraulic press. In this manner all air bubbles and inequalities areremoved and the layers are forced into intimate contact, leaving asmooth and level surface. If the resilient layer is not speciallyprepared a coating 4 should be placed thereon containing a pigmentwhich'may be black or any other desired color, and also an abrasive toform a proper frictional surface and present a tooth to the crayon. Asuitable mixture for this purpose is suggested in a former patent issuedto me January 23, 1906, No. 810,623, upon which my present invention isan improvement. As above stated I prefer to use a specially preparedmaterial on the metallic foundation, which may be made by incorporatinga pigment such as lamp black and an abrasive such as powdered pumiceeach to the extent of about 3% of the bulk of the paper pulp in thepaper pulp in the process of manufacture which is then dried andcalendered in the usual manner. By so doing the colored and abrasivesurface of the board is self renewed as fast as it Wears and noapplication of a new surface is required.

I claim:

1. A blackboard comprising a metallic foundation, and an independentlyformed layer of brous resilient material secured to the outer face ofthe foundation said layer Ibeing provided with a pigmented abrasivewearing face.

2. A blackboard comprlsmg a flexible metallic foundation, and a layer offibrous re-Y silient material secured to the outer face of thefoundation said layer being provided with a pigmented abrasive wearingface.

3. A blackboard comprising a flexible metallic foundation, a layer ofpaper or other brous resilient material cementedV to the outer face ofthe foundation, and a pigmented wearing face on the surface of the saidresilient layer.

4. A blackboard ,comprising a metallic foundation, and an independentlyformed resilient layer secured thereto, said layer having suitablecoloring matter and abrasive material incorporated in the body thereofto provide a wearing face.

5. A wearing face for blackboards consisting of a sheet of fibrousresilient material having suitable coloring matter and abrasive materialincorporated in the body thereof to my hand, this 2nd day of June A. D.1909, provide a gwlfeaiong time. b in the presence of tWo subscribingWitnesses.

6. n a aci oar the com ination with a resilient ilorous Wearing face, ofa. metallic THOMAS H' CO STELLO' 5 back and an adhesive layerl to securethe Witnesses:

back to the face. Y C. K. CHAMBERLAIN,

In Witness whereof, I have hereunto set A. S. PHILLIPS.

Copies of this patent may be obtained'for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

